Airtight equipment in a rotary pump

ABSTRACT

Means for improving the fluid tightness of a rotary pump. A bisected annular plate is provided between each end of the rotor and the casing through which the drive shaft extends, one-half of the plate being on the intake side of the casing and the other half being on the discharge side of the casing. The half of the plate on the intake side is drawn toward the rotor by the reduced pressure at the intake side, while the half of the plate on the discharge side is urged away from the rotor by the pressure.

United States Patent Kazuo Satake No. 77, 2-cho,0htari Minami-Machi,Sakai-shi, Japan May 15, 1969 Apr. 20, 1971 lnventor Appl. No. FiledPatented AIRTIGHT EQUIPMENT IN A ROTARY PUMP 3 Claims, 3 Drawing Figs.

US. Cl 418/133 Int. Cl F010 19/08, F040 27/00 Field 01' Search 103/216,144, 126,120, 1323;230/152;91/14l;418/103; 418/131-135 References CitedUNITED STATES PATENTS Wilsey l03/l26(S)UX 1,996,875 4/1935 McCann91/141X 3,184,156 5/1965 Welch et al.... 230/152 3,187,993 6/1965 Rhodes230/152 3,303,793 2/1967 Morita 103/126(S)UX 3,327,638 6/1967Scognamillo 103/136 3,479,962 11/ 1969 Pettibone 103/ 136 PrimaryExaminer-Carlton R. Croyle Assistant Examiner-John .I VrablikAttorney-Wenderoth, Lind & Ponack ABSTRACT: Means for improving thefluid tightness of a rotary pump. A bisected annular plate is providedbetween each end of the rotor and the casing through which the driveshaft extends, one-half of the plate being on the intake side of thecasing and the other half being on the discharge side of the casing. Thehalf of the plate on the intake side is drawn toward the rotor by thereduced pressure at the intake side, while the half of the plate on thedischarge side is urged away from the rotor by the pressure.

PATENIEMm Ian SHEET 1 UF 3 N m a g at INVENT OR Kazuo Satake ATTORNEYPATENTEU APR 20 I97! SHEET 2 0F 3 m, q z.

INVENTOR Kazuo Satake avwxfi) 3M ATTORNEY PATENTED APRZO IHTI SHEET 3 or3 INVENT OR Kazuo-Satake BYLJMQLSQQW ATTORNEY tllllt'llfirfll'f'EOTJWMENT IN A ROTARY PUMP This invention relates to equipment withwhich to improve the airtightness between the terminal surface of arotor and the casing of a rotary pump.

In relation to improvement of the efficiency of a rotary pump the ideawhich is readily conceivable is to interpose an airtight plate betweenthe rotor and the casing. However, from mere interposition of a singledisc-shaped airtight plate between the rotor end and the pump casing nosatisfactory airtight effect is obtainable, even when the said airtightplate is pressed to the rotor end with relatively great force.

This is due to the fact that a backward pressure generated on the sideof the discharge outlet at the time of the operation of the pump ispropagated to the airtight plate inside the casing, giving the saidplate an outwardly curved distortion, with the result that a gap arisingbetween the airtight plate and the rotor end deprives the said airtightplate of its satisfactory function.

The object of the invention is to remarkably enhance the efficiency ofthe pump by eliminating the aforementioned defect and bringing theairtight plate into closer contact with the terminal surface of therotor during the operation of the pump, so that the airtight functionwill be maintained as near to perfection as possible.

The foregoing object is attainable by improving the airtight plate, anda preferred embodiment thereof will be illustrated in detail by thedescription set forth hereinunder and the drawings annexed hereto.

Modifications and changes with regard to the particulars of theconstruction are to be included in the claims which will appearhereinafter.

1n the drawings:

FlG. l is a longitudinally sectional elevation of a rotary pump providedwith the airtight equipment of the invention.

FIG. 2 is a lateral view of a longitudinal section of the rotary pump ofHG. ll.

FIG. 3 is a perspective view of a part of the said rotary pumpdisassembled.

1n the airtight equipment according to the invention the airtight plateto be interposed between the rotor end and the casing is divided intotwo sections, one for the side of the discharge area and the other forthe side of the suction area.

in F105. l to 3 the numeral ll indicates the airtight plates of theinvention, two semicircular plates forming a single disc when titted toeach other at the straight rims 12 thereof which correspond to thechords of the semicircles.

On the part of the straight rim 12 of each airtight plate iseccentrically formed a semicircular hollow R3, the said hollows 13 whenthe two airtight plates 111 are fitted together at the respectivestraight rims 12 thereof constituting a hole through which a rotaryshaft penetrates.

Each of the airtight plates 11 is provided with a pair of rotationarresting pins M respectively, which serve to arrest the rotation of theairtight plates 11 by fitting into a plurality of holes 15 formed in theinternal surface of each casing cover E5.

The numeral 117 designates a pump casing, on the external peripherythereof a discharge outlet 30 and a suction inlet 31 being providedrespectively. On both sides of the casing 17 are fastened theaforementioned covers 15 with bolts, inside the casing 17 being fixed acylindrical liner 18 having holes 32, 33 which communicate with thedischarge outlet 30 and the suction inlet 51;, sealed packings 19 beinginterposed between the casing t7 and the cover 15.

The numeral 2% indicates a rotor shaft, which is revolvably fixed to theright and the left covers 15 through bearings 21. The said rotor shaft2b is fixed in parallel with the cylindrical liner lb inside the casing17 and in an upwardly eccentric state, the rotor body 22'being fixedconcentrically with the rotor shaft 20 at the area where the rotor shaft241 is located inside the casing l7. Since the rotor body 22 iseccentric against the liner 1%, it is so arrangedthat the rotor body 22may be freely revolvable inside the liner 118 by making the diameter ofthe rotor body 22 considerably smaller than the bore of the liner lib.

On the said rotor body 22 a plurality of, say six, deep grooves 23 areformed at regular intervals running from the external periphery towardthe center thereof. In each of the said grooves 23 is slidably fitted avane 24.

There exists some space between both terminal rims of the foregoing vane24 and the right and the left covers 15 respectively, the aforementionedairtight plates 11 being inserted into the'said space, the rotor shaft20 penetrating through the hollows 13 of the respective airtight plates11.

[t is so arranged that both ends of the rotor body 22 be positionedfurther inside of both terminal rims of each vane 24, the externalperiphery of a mouth ring 25 which is loosely fitted to the rotor shaft20 on the outside at both ends of the rotor body 22 being in contactwith the inside surface of both ends of the vane 24 respectively, theexternal rim of the vane 24 being constantly slidable on the internalsurface of the liner 1%.

One end of the rotor shaft 20 protrudes outwardly through the centralhole of alid 26 which is fastened with bolts to the outside of one ofthe covers 15, a V-pulley 27 being fixed to the end thereof, the otherend of the rotor shaft 20 terminating at the external end of the cover15 on that side and being covered by a lid 28 which is fastened withbolts to the outside of the cover 15. Oil seals 29 are fitted to theparts where the rotor shaft runs through each cover 15.

Alternatively both ends of the rotor body may be brought in contact withthe airtight plates 11 by omitting the mouth ring 25.

The foregoing rotor body 22, the mouth ring 25 and the vanes 24 aregiven the general name of rotor.

In the rotary pump equipped with an airtight plate 11 which is dividedinto two sections as described above, if the rotor shaft 21] is revolvedby driving the V-pulley 27 by means of an appropriate motor, water orthe like fluid sucked through the suction inlet 31 is discharged towardthe. discharge outlet 30 by the rotor in the same way as in the case ofthe ordinary rotary pump.

When the fluid runs as described above, the semicircular airtight plate11 which faces the rotary chamber located on the side of the dischargeoutlet from the center where the straight rims 12 of the right and theleft airtight plates 11 meet as shown in FIG. 1, that is, which facesthe side of the discharge area, is pressed outwardly under thedischarging pressure of the fluid, the other semicircular airtight plate11 which is so provided as to face the suction area on the side of thesuction inlet 31 is sucked toward the rotor by the suction inside therotary chamber on that side.

in the illustrated mechanism, therefore, the airtight plate 11 for theside of the suction area is tightly fitted to the mouth ring 25 and theterminal rims of the vanes 24. Also in the system wherein the mouth ring25 is omitted, the airtight plate 11 is closely fitted to the rotor body22 and the terminal rims of the vanes 24. Airtightness being thusmaintained, the fluid suction of the suction part is remarkablyincreased.

In this invention, as described heretofore, it is so arranged that theairtight plate for the side of the discharge area may not affect theairtight plate for the side of the suction area by providing an airtightplate which is divided into two sections, one for the discharge area andother for the suction area respectively. As a result, the airtight plate11 for the side of the suction area is closely fitted to the rotorwithout being affected by the pressure on the side of the dischargearea, the suction of the rotor being thus remarkably increased. Thisinvention therefore has an advantage in that the efficiency of the pumpcan be greatly enhanced.

The airtight plate 11, though its revolution together with the rotor isprevented by the rotation arresting pins 14 which are fitted into thefitting holes 16 in the casing covers 15, is freely movable in the axialdirection of the rotary shaft, as a result of which the airtight platefl and the rotor remain in close contact with each other, even when thefriction surface of the airtight plate llll and that of the rotor areworn, thus preventing the efficiency of the pump from decreasing.

Furthermore, the airtight plate 11 for the side of the discharge area isof the identical shape as that for the side of the suction area.Therefore, even when the discharge outlet and the suction inlet arereversed, i.e. when the pump is of the reversible type, the airtightplate 11 which happens to be on the side of the suction area comes inclose contact with the rotor, maintaining satisfactory suction, with theresult that the efficiency of the pump is never impaired by reversingthe pumping direction.

Moreover, the airtight plate ll for the side of the discharge area ispressed to the internal surface of the casing cover 15 by thedischarging pressure, but neither the casing cover 15 nor the airtightplate 11 pressed thereto is worn out because they are stationary.Therefore, if the airtight plate 11 for the side of the suction area isworn, it can be replaced with the airtight plate 11 for the side of thedischarge area, as a result of which a high pumping efficiency ismaintainable without the trouble of changing the said worn airtightplate 11 for a new one.

ln the embodiment illustrated, the airtight plate 11 for the side of thedischarge area and that for the side of the suction area are separatedfrom each other with the rotary shaft between them, but both plates 11can be movably connected together with connecting pieces of appropriateflexibility. Besides, it is desirable that both sides of each revolvablevane 24 should be prevented from scratching the straight rims 12 of theairtight plate 11 by giving appropriate roundness to both sides of thesaid straight rims.

lclaim:

1. In a rotary pump including a casing having a pair of casing covers, arotor shaft mounted in said covers and extending through the interior ofsaid casing, and a rotor mounted on said shaft within said interior ofsaid casing, said casing having a suction inlet and a discharge outletextending into and from'said interior, whereby said interior includes asuction area and a discharge area and the path of pumping of said rotorpump is transverse to the axis of said shaft from said suction inlet,into said suction area, then into said discharge area and out saiddischarge outlet; the improvement comprising a pair of discs surroundingsaid shaft and positioned between the terminal edges of said rotor andsaid covers, each of said discs comprising a pair of semicircularplates, the first of said plates of each of said discs being positionedin said suction area, and the second of said plates of each of saiddiscs being positioned in said discharge area.

2. In a rotary pump as claimed in claim 1, wherein said covers haveholes therein, and said plates have arresting pins positioned in saidholes, thereby preventing rotation of said plates when said shaftrotates.

3. ln a rotary pump as claimed in claim 1, wherein said pair of platesof each of said discs are connected by flexible connecting pieces.

1. In a rotary pump including a casing having a pair of casing covers, arotor shaft mounted in said covers and extending through the interior ofsaid casing, and a rotor mounted on said shaft within said interior ofsaid casing, said casing having a suction inlet and a discharge outletextending into and from said interior, whereby said interior includes asuction area and a discharge area and the path of pumping of said rotorpump is transverse to the axis of said shaft from said suction inlet,into said suction area, then into said discharge area and out saiddischarge outlet; the improvement comprising a pair of discs surroundingsaid shaft and positioned between the terminal edges of said rotor andsaid covers, each of said discs comprising a pair of semicircularplates, the first of said plates of each of said discs being positionedin said suction areA, and the second of said plates of each of saiddiscs being positioned in said discharge area.
 2. In a rotary pump asclaimed in claim 1, wherein said covers have holes therein, and saidplates have arresting pins positioned in said holes, thereby preventingrotation of said plates when said shaft rotates.
 3. In a rotary pump asclaimed in claim 1, wherein said pair of plates of each of said discsare connected by flexible connecting pieces.